基于行波分解的泛频响函数法在高承台桩灾后无损检测评估中的应用研究

摘要

针对现有方法在高承台桩灾后无损检测和评估中的局限性,提出了基于行波分解的泛频响函数法.将承台对桩顶的作用简化为黏弹性支撑边界,采用自行编制的波动分析程序求得检测截面处的泛频响函数;通过在该位置虚拟输入半正弦激励脉冲,将泛频响函数所包含的信息转换到时域内进行分析,得到检测截面以下虚拟隔离单桩桩顶的速度时域响应曲线;分析了相关参数对泛频响函数和由此转换而来的时域响应的影响.结果表明,基于行波分解的泛频响函数法,能在不破坏上部结构的前提下,完全消除其对检测结果的影响,从而将复杂结构体系下的基桩转化到单桩模式下进行检测分析,简化了检测步骤,降低了分析难度.%The universal frequency response function method based on traveling wave decomposition was put forward aiming at the limitation of existing methods in the nondestructive testing and assessment of post-disaster tall platform pile foundations.The reaction of the pile cap on the pile head was simplified as a complex impedance,and the universal frequency response function at the test section was calculated according to the wave equation analysis.Then,the information contained in the universal frequency response function was switched from the frequency domain to the time domain by virtually applying a half-sine pulse at the test section.As a result,the time domain response curve of the virtually isolated single pile below the test section was obtained.Finally,a parametric study was undertaken to investigate the influences of pile-soil parameters on the universal frequency response function as well as the time domain response transformed from it.The results show that the method proposed can completely eliminate the influence of thesuperstructure,which simplifies the testing procedure and reduces the difficulty of analysis.